1. Field
The present disclosure relates generally to manufacturing and in particular to managing vapors in an interior area. Still more particularly, the present disclosure relates to a method and apparatus for an exhaust system to remove flammable/explosive vapors.
2. Background
In manufacturing aircraft, many different operations may be performed to produce an aircraft ready for service. These operations include, for example, without limitation, manufacturing an airframe, skin panels, ailerons, and other suitable components. Additionally, these operations also may include installing electrical systems, hydraulic systems, aircraft seats, monuments, and other suitable items. These components may be bolted, joined, bonded, or otherwise attached to each other.
One operation that may be performed involves painting the exterior of the aircraft. Although the different parts may be painted and/or coated prior to joining or assembling the parts, other components such as, for example, without limitation, bolts used to join parts may require painting after assembly. Additionally, painting operations in the interior of the aircraft also may occur to provide, without limitation, desired aesthetics or corrosion resistance.
Painting and/or other operations in an interior of an aircraft may result in various flammable/explosive vapors and/or mists being generated. The overspray can contaminate other interior surfaces. An ignitable vapor may be a flammable vapor or an explosive vapor. In these examples, the code requirements may be, for example, without limitation, National Fire Protection Association (NFPA) codes and/or standards.
With these types of situations, exhaust systems may be used to ventilate and/or remove these vapors and/or mists from the interior of the aircraft. A flexible duct may be used to remove vapors and/or mists from a portion of an aircraft in which the vapors may be contained with or without containment curtains or local exhaust hoods/devices to entrain the vapors/mists and extract the vapor/mists to the exterior of the aircraft.
These vapors and/or mists may be filtered and otherwise processed to remove flammable components from the air. The processed air may be allowed to recirculate under code requirements or exhausted to the outside of the facility following proper procedures. Code requirements may be, for example, without limitation, those from the National Fire Protection Association and other suitable entities.
Depending on the location in which vapors and/or mists may be generated in the aircraft and the location of the doors or other portals from the aircraft exterior into the interior of the aircraft, flexible ducts of various lengths may be needed. These flexible ducts may be, for example, without limitation, forty feet, fifty feet, eighty feet, or some other suitable length appropriate for production personnel convenience of assembly.
The flexible ductwork may be required by National Fire Protection Association codes to maintain conductivity between sections and to a grounded ventilation/exhaust system for dissipating static electricity charges accumulating in the exhaust system. Conductive flexible ductwork also may be required by code to be static dissipative of static charge to an approved grounding location, such as, for example, without limitation, grounded equipment or building ground location. Conductive flexible duct work may not require the same low resistance conductivity as in wiring used for other purposes.
In many situations, long lengths of flexible ducts may be difficult to handle. For example, without limitation, a duct that may be sixty feet long may be difficult to move into place within an aircraft. Different lengths of flexible ducts may be used to reduce some of the handling difficulty. This type of solution, however, may increase the cost and may interrupt or delay operations in manufacturing aircraft in the event that a duct having an appropriate length is unavailable.
Pigtails have been used to connect flexible ducts together and may conform to codes and/or regulations. Pigtails, however, may not be a practical solution for maintaining static discharge conductance. A pigtail may be a wire used between duct sections. Pigtails, however, may be inconvenient to production personnel and may have inconsistent conductivity and may be prone to repeated failure and/or breakage.
Therefore, it would be advantageous to have a method and apparatus that overcomes the problems described above.